The present invention relates to an ozone storage/recovery method and a system therefor, capable of generating ozone with use of low-priced night electricity in the main, storing it, and discharging it as required.
Ozone is a clean oxidizing agent that is free from secondary environmental pollution and easy to handle, and therefore, is widely used in the fields of sterilization, cleaning, oxidative bleaching, etc.
In general, however, ozone is decomposed so easily that it cannot be stored in a gas cylinder or the like. Conventionally, therefore, ozone is used hot from a silent-discharge ozone generator, ozone generator with an ultraviolet lamp, water-electrolysis ozone generator, etc.
More specifically, the ozone generator is installed on the scene of use, and ozone is obtained by operating the generator only when it is needed. According to this method, however, it is hard for users to cope with load fluctuations.
Ozone is produced by using the silent-discharge ozone generator or water-electrolysis ozone generator in the main. However, the cost of power supply for operating these generators accounts for a high percentage in the unit cost of ozone manufacture. Since the demand for ozone is restricted by time and fluctuates, on the other hand, there has been a request for the development of an ozone storage device from which an ozone-containing gas with a given concentration can be taken out as required.
To attain this, the gas may possibly be liquefied when it is stored into an adsorbent so that it can be taken out when needed. However, these storage methods have the following problems.
In general, ozone easily decomposes and liquefying it requires great energy, so that the liquefying method is impractical.
Silica gel is a well-known ozone adsorbent. Its ozone adsorptivity is so low. Also, the silica gel strongly adsorbs water, if any, in advance of ozone. Thus, water is stored in silica gel, so that the ozone adsorption amount is lowered correspondingly. Further, a sizable amount of ozone decomposes while it is being adsorbed by silica gel, so that the ozone recovery is reduced considerably. For the long run, furthermore, silica gel may possibly be powdered due to the adsorption of water. In consequence, the ozone storage apparatus that uses silica gel lacks in utility.
An object of the present invention is to provide an ozone storage/recovery method, which uses an ozone adsorbent contained a specific high-silica material that has high ozone adsorptivity and high ozone retention ratio even in a watery system, whereby ozone can be produced with use of low-priced electricity, such as night electric power, stored, and recovered to be supplied when necessary.
Another object of the invention is to provide an ozone storage/recovery system, which can produce ozone with use of low-priced electricity, such as night electric power, store it, and when necessary, recover and supply it, thus enjoying lower running cost.
According to the invention, there is provided an ozone storage/recovery method, which comprises steps of:
a process for supplying an ozone-containing gas, generated by an ozone generator, to an ozone adsorbent tank filled with an ozone adsorbent contained at least one high-silica material selected from the group consisting of a high-silica pentasil zeolite, a dealumination faujasite and a mesoporous silicate, causing the adsorbent to adsorb ozone at a temperature of 0xc2x0 C. or below, and storing the ozone; and
a process for desorbing the ozone adsorbed by the adsorbent in the ozone adsorbent tank and recovering the ozone from the adsorbent tank.
According to the invention, moreover, there is provided an ozone storage/recovery system, which comprises:
an ozone generator;
an ozone adsorbent tank connected to the ozone generator by means of an ozone-containing gas supply pipe and filled with an ozone adsorbent contained at least one high-silica material selected from the group consisting of a high-silica pentasil zeolite, a dealumination faujasite and a mesoporous silicate;
a compressor and an on-off valve successively attached to the ozone-containing gas supply pipe from the ozone generator side;
an insulated container containing the adsorbent tank therein;
a cooler and a heater attached to the insulated container; and
an ozone recovery duct having an on-off valve connected to the adsorbent tank.
According to the invention, furthermore, there is provided an ozone storage/recovery system, which comprises:
an ozone generator;
an ozone adsorbent tank connected to the ozone generator by means of an ozone-containing gas supply pipe and filled with an ozone adsorbent contained at least one high-silica material selected from the group consisting of a high-silica pentasil zeolite, a dealumination faujasite and a mesoporous silicate;
a compressor and an on-off valve successively attached to the ozone-containing gas supply pipe from the ozone generator side;
an insulated container containing the adsorbent tank therein;
a cooler attached to the insulated container;
a purging gas supply pipe connected to the absorbent tank;
an on-off valve and a heater successively attached to the purging gas supply pipe from the absorbent tank side; and
an ozone recovery duct having an on-off valve connected to the adsorbent tank.
According to the invention, moreover, there is provided an ozone storage/recovery system, which comprises:
an ozone generator;
an ozone adsorbent tank connected to the ozone generator by means of an ozone-containing gas supply pipe and filled with an ozone adsorbent contained at least one high-silica material selected from the group consisting of a high-silica pentasil zeolite, a dealumination faujasite and a mesoporous silicate;
a compressor and an on-off valve successively attached to the ozone-containing gas supply pipe from the ozone generator side;
an insulated container containing the adsorbent tank therein;
a cooler attached to the insulated container;
an ozone recovery duct connected to the adsorbent tank; and
an on-off valve and exhaust means successively attached to the ozone recovery duct from the absorbent tank side.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.